The Clinical Core provides well-characterized patients and control subjects for novel interdisciplinary research in Center-related and collaborative projects. New subjects added to the current Longitudinal Case Series will include only persons with normal aging and patients with mild cognitive impairment (MCI) or mild dementia. This will meet the needs of Center investigators and allow them to conduct cutting-edge research to understand better the clinical and neuropathological changes that distinguish the earliest stages of Alzheimer's disease (AD) from normal aging and from other neurodegenerative diseases commonly seen in the elderly. All subjects receive comprehensive examinations, including neuropsychological, laboratory and imaging studies, and are classified at a consensus conference using explicit diagnostic inclusion and exclusion criteria. Subjects identify a study partner who serves as an informant and are encouraged to name a health care advocate and give provisional consent for an autopsy to facilitate research. Annual assessments provide longitudinal clinical and neuropsychological data. The Core refers potential subjects to clinical research projects, shares data with the National Alzheimer's Coordinating Center, and collects biological samples following agreed upon protocols for multi-center projects. In close collaboration with the Education Core, the Clinical Core serves as the primary contact point with the community and assists with educational materials and activities to promote participation in clinical studies, stimulate the interest of trainees and new investigators, and disseminate research advances widely. In conjunction with the Minority Satellite Diagnostic and Treatment Center at the Ypsilanti Family Practice Center, which serves large African-American and Hispanic communities, the Clinical Core ensures a diverse research population from which to draw potential subjects. The Core also performs developmental work using its collected longitudinal data to provide Center investigators with metrics describing individual clinical transitions and rate of disease progression in enrolled participants.